1. Field of the Invention
The present invention relates to a surgical instrument which operates a treatment section disposed in a distal end of an insertion section by an operation section disposed in a proximal end of the insertion section.
2. Description of the Related Art
For example, U.S. Pat. Nos. 5,383,888, 5,417,203, 5,549,637 etc., disclose surgical instruments. In these surgical instruments, distal ends of treatment sections can be rotated.
In the surgical instruments disclosed in U.S. Pat. Nos. 5,383,888 and 5,417,203, the distal ends of the treatment sections can be rotated, and tip-tools disposed in the distal ends of the treatment sections can be opened/closed. In the surgical instrument described in U.S. Pat. No. 5,383,888, an opening/closing operation is carried out utilizing the tension of a flexible cable connected to the tip-tool. In the tip-tool of the surgical instrument described in U.S. Pat. No. 5,417,203, a joint portion to realize rotation of the tip-tool is made of a shape memory alloy.
The surgical instrument disclosed in U.S. Pat. No. 5,549,637 is a surgical stapler. In the distal end of the treatment section of the stapler, three joints are disposed to rotate the distal end. Each joint has a rotational angle of 60°. A pair of bands is connected to the distal end of the treatment section of the stapler. The three joints in the distal end of the treatment section are sequentially rotated by tensing or slackening the bands. Accordingly, the distal end of the treatment section of the stapler can be changed in direction by 180° (6°×3) with respect to an insertion direction of the stapler.